Optical encoder for detecting rotational and axial movement

ABSTRACT

Embodiments of the present disclosure provide an optical encoder for an electronic device. The optical encoder comprises an elongated shaft having an encoding pattern made up of axial markings and radial markings. The encoding pattern may be disposed around a circumference of the elongated shaft. The optical encoder also includes an optical sensor. In embodiments, the optical sensor includes an emitter and a photodiode array. The emitter causes light to shine on the encoding pattern. The encoding pattern reflects the light back to the photodiode array and the photodiode array determines movement of the shaft based on the reflected light.

TECHNICAL FIELD

The present disclosure is directed to optical encoders for electronicdevices. Specifically, the present disclosure is directed to an opticalencoder in which markings of an encoding pattern of the optical encoderhas both an axial component and a radial component disposed around acircumference of the shaft of the optical encoder. In addition, a lightsource and a photodiode array are aligned in various patterns withrespect to the optical encoder so as to detect the rotational and linearmovement of the shaft of the optical encoder.

BACKGROUND

Many devices, including mechanical, electronic and computerized devices,may utilize various types of encoders for obtaining and collecting dataabout the particular device. For example, a rotary encoder may be usedto collect information about a position of a component in the device, adirection in which the component is moving, and/or as a speed of themovement of the component. However, some of these encoders are notsuitable for use in a small or compact space that may be required for anelectronic device having a small form factor.

It is with respect to these and other general considerations thatembodiments have been made. Also, although relatively specific problemshave been discussed, it should be understood that the embodiments shouldnot be limited to solving the specific problems identified in thebackground.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription section. This summary is not intended to identify keyfeatures or essential features of the claimed subject matter, nor is itintended to be used as an aid in determining the scope of the claimedsubject matter.

Embodiments of the present disclosure provide an optical encoder for anelectronic device. The optical encoder comprises an elongated shafthaving an encoding pattern that includes an axial component and a radialcomponent. The axial component and the radial component may consist of aplurality of stripes or markings that are disposed around acircumference of the elongated shaft. The optical encoder also includesan optical sensor. In embodiments, the optical sensor includes anemitter and a photodiode array. The emitter is configured to emit lightthat is reflected off of the encoding pattern and received by thephotodiode array.

In another embodiment, an electronic device is provided. The electronicdevice includes a processor, a memory and an optical encoder. Theoptical encoder includes an elongated shaft having an encoding pattern.The encoding pattern includes an axial component and a radial componentmade up of a plurality of markings that are arranged around acircumference of the elongated shaft.

In yet another embodiment of the present disclosure, a method fordetecting movement of a shaft contained within a housing of anelectronic device is disclosed. The method includes causing a lightsource to emanate light on the shaft. The shaft includes an encodingpattern that has an axial component and a radial component disposedaround a circumference of the shaft. The encoding pattern reflects thelight into a photodiode array. When the reflected light is received bythe photodiode array, rotational and linear movement of the shaft may bedetermined.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an exemplary electronic device according to one ormore embodiments of the present disclosure;

FIG. 1B illustrates a cross-sectional view of the electronic device ofFIG. 1A according to one or more embodiments of the present disclosure;

FIG. 1C illustrates a cross-sectional view of the electronic device ofFIG. 1A according to an alternate embodiment of the present disclosure

FIGS. 2A-2C illustrate exemplary encoding patterns of an optical encoderaccording to one or more embodiments of the present disclosure;

FIG. 3 illustrates an exemplary segmented photodiode array according toone or more embodiments of the present disclosure;

FIGS. 4A-4C illustrate exemplary current output graphs of a photodiodearray according to embodiments of the present disclosure;

FIGS. 5A-5B illustrate an optical encoder having components of anoptical sensor according to one or more embodiments of the presentdisclosure; and

FIG. 6 illustrates a method for detecting movement of a component of anelectronic device according to one or more embodiments of the presentdisclosure.

DETAILED DESCRIPTION

Various embodiments are described more fully below with reference to theaccompanying drawings, which form a part hereof, and which show specificexemplary embodiments. However, embodiments may be implemented in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the embodiments to those skilled in the art. Thefollowing detailed description is, therefore, not to be taken in alimiting sense.

In some electronic devices, one or more components of the electronicdevice may be configured to move in a variety of directions. Further,each direction in the variety of directions may have a specific purposeor cause a specific outcome. For example, a crown of a time keepingdevice may be configured to rotate clockwise and counter-clockwisemanner in order to move hands or dials that are displayed or otherwisepresent on a face of the time keeping device. In addition, the crown mayalso be configured to move linearly from a first position to a secondposition. For example, the crown may be pressed inward or pulled outwardto accomplish a specified task or perform a particular function.

In the examples described above a single optical encoder may be used todetect both the rotational movement of the crown as well as linearmovement of the crown. More specifically, embodiments of the presentdisclosure describe an optical encoder that detects rotational movement,rotational direction and/or rotational speed of a component of theelectronic device as well as linear movement and speed of the componentof the electronic device. Once the movement has been determined, thisinformation may be used to output or change information and images thatare presented on a display or user interface of the electronic device.

As will be explained below, the optical encoder of the presentdisclosure includes a light source, a photodiode array, and a shaft.However, unlike typical optical encoders, the optical encoder of thepresent disclosure utilizes an encoding pattern disposed directly on theshaft. For example, the encoding pattern includes a number of light anddark markings or stripes that are axially disposed and radially disposedalong the shaft. Each stripe or combination of stripes on the shaft maybe used to identify a position of the shaft.

For example, as light is emitted from the light source and reflected offof the shaft into the photodiode array, a position, rotation, rotationdirection and rotation speed of movement of the shaft may be determined.Once the rotation direction and speed are determined, output, images andother information that are presented on the display or user interface ofthe electronic device may be updated.

In other embodiments, the shape or form of the shaft of the encoder maybe used to determine a position linear movement and direction, linearspeed, rotational movement, rotational direction rotation speed of theshaft. For example, the shaft may be fluted or have a number of channelsthat cause the light to be reflected in a number of differentdirections. Accordingly, a diffractive pattern may be used to determineeach of the movements described above.

FIG. 1A illustrates an exemplary electronic device 100 according to oneor more embodiments of the present disclosure. In certain embodiments,the electronic device 100 may be a portable computing device. Suchexamples include cell phones, smart phones, tablet computers, laptopcomputers, time-keeping devices, computerized glasses and other wearabledevices navigation devices, sports devices, accessory devices,health-monitoring devices, medical devices and the like. In one example,and as shown in FIG. 1, the electronic device 100 may be a wearableelectronic device. The electronic device 100 may include a housing 110as well as a display 120, a button 130 (or other input mechanism) and acrown 140.

In many examples, the wearable device, such as is depicted in FIG. 1A,may include a processor coupled with or in communication with a memory,one or more communication interfaces, output devices such as displaysand speakers, and one or more additional input devices such as buttons,dials, microphones, or touch-based interfaces. The communicationinterface(s) can provide electronic communications between thecommunications device and any external communication network, device orplatform, such as but not limited to wireless interfaces, Bluetoothinterfaces, Near Field Communication interfaces, infrared interfaces,USB interfaces, Wi-Fi interfaces, TCP/IP interfaces, networkcommunications interfaces, or any conventional communication interfaces.The wearable electronic device 100 may provide information regardingtime, health, statuses or externally connected or communicating devicesand/or software executing on such devices, messages, video, operatingcommands, and so forth (and may receive any of the foregoing from anexternal device), in addition to communications.

In embodiments, the display 120 of the electronic device 100 may be atouch-sensitive display having an input area. The input area may coverthe entire display 120 or substantially all of the display 120. Inanother embodiment, the input area may cover only a portion of thedisplay 120.

The display 120 is configured to output a user interface that displaysinformation about the electronic device 100 as well as other informationthat is stored in a memory of the electronic device 100. For example,the user interface may present information corresponding to one or moreapplications that are being executed on the electronic device 100. Suchapplications may include a time keeping application, an emailapplication, a phone application, a calendaring application, a gameapplication and the like.

In embodiments, the button 130 or the crown 140 may be used to select,adjust or change various images that are output on the display 120. Forexample, if the display 120 of the electronic device 100 is displaying atime keeping application, the crown 140 may be rotated in eitherdirection to change or adjust the position of the hands or the digitsthat are displayed for the time keeping application. In otherembodiments, the crown 140 may be rotated to move a cursor or other typeof selection mechanism from a first displayed location to a seconddisplayed location in order to select an icon or move the selectionmechanism between various icons that are output on the display 120.Likewise, the crown may be pulled, pushed or pressed to provide anotherinput to the device 100.

Although not shown in FIG. 1A, the electronic device 100 may alsoinclude various additional components that assist in the overalloperation of the device. For example, the electronic device 100 mayinclude a sensor, a microphone, a processor, a memory, and the like.Further, the crown 140 and the button 130 may interact with one or moreof the components listed to facilitate operation of the electronicdevice 100.

The electronic device 100 may also include a band 150 that may be usedto secure or attach the electronic device 100 to a user. Otherattachment mechanisms, such as, for example, a strap, a lanyard or othersuch attachment mechanism may also be used.

In certain embodiments, electronic device 100 may also include akeyboard or other input mechanism. Additionally, the electronic device100 may include one or more components that enable the electronic device100 to connect to the Internet and/or access one or more remotedatabases or storage devices. The electronic device 100 may also enablecommunication over wireless media such as acoustic, radio frequency(RF), infrared, and other wireless media mediums. Such communicationchannels may enable the electronic device 100 to remotely connect andcommunicate with one or more additional devices such as, for example, alaptop computer, tablet computer, mobile telephone, personal digitalassistant, portable music player, speakers and/or headphones and thelike.

FIG. 1B and FIG. 1C illustrate cross-sectional views of the electronicdevice 100 of FIG. 1A according to one or more embodiments of thepresent disclosure. Referring to FIG. 1B, the electronic device 100includes an optical encoder that consists of a shaft 160, a light source170 and a photodiode array 180. Although a photodiode array isspecifically mentioned, embodiments disclosed herein may use varioustypes of sensors that are arranged in various configurations fordetecting the movement described herein. For example, the movement ofthe shaft 160 may be detected by an image sensor, a light sensor such asa CMOS light sensor or imager, a photovoltaic cell or system, photoresistive component, a laser scanner and the like.

The optical encoder is used to determine positional data of the crown140. More specifically, the optical encoder may be used to detectrotational and translational movement of the crown 140 including thedirection of each of the movements, the speed of each of the movementsand so on. The movement may be rotational movement, translationalmovement, angular movement, and various combinations. The opticalencoder may also be used to detect the degree of the change of rotationof the crown 140 and/or the angle of rotation of the crown 140 as wellas the speed and the direction of the rotation of the crown 140. Oncethe movement data of the crown 140 is determined, one or more graphics,images or icons on the display 120 of the electronic device 100 may beupdated or altered accordingly.

For example, and continuing with the time keeping application examplediscussed above, the crown 140 may be rotated in a clockwise manner inorder to change the displayed time. The optical encoder of the presentdisclosure will detect the original starting position of the crown 140,the rotational movement of the crown 140 in the clockwise direction, andwill also detect the speed at which the crown 140 is being rotated. As aresult, the displayed hands of the time keeping application may rotateor otherwise move in a similar direction and speed.

In another example, the crown 140 of the electronic device may beactuated in a translational manner such as shown by arrow 185. Forexample, the crown 140 may be pressed inward toward the housing 110 toselect a displayed option. In another example, the crown 140 may bepulled outward to perform a particular function. In still yet anotherexample, the crown may be actuated in a translational manner and in arotational manner simultaneously or substantially simultaneously.Regardless of the movement, the optical encoder disclosed herein maydetect the movement and output or change displayed data accordingly.

Referring back to FIG. 1B, the optical encoder may include a shaft 160.The shaft 160 may be coupled to the crown 140. In another embodiment theshaft 160 may be an extension of the crown 140. That is, the crown 140and the shaft 160 may be manufactured from a single piece. As the shaft160 is coupled to, or is otherwise a part of the crown 140, as the crown140 rotates or moves in a particular direction and at a particularspeed, the shaft 160 also rotates or moves in the same direction andwith the same speed.

The shaft 160 of the optical encoder includes an encoding pattern 165.As discussed, the encoding pattern 165 is used to determine positionalinformation about the shaft 160 including translational movement,rotational movement, angular displacement as well as movement speed. Theencoding pattern 165 may include a plurality of light and dark stripessuch as shown in FIG. 1B.

In certain embodiments, the encoding pattern 165 may have an axialcomponent and a radial component. For example, the encoding pattern 165may include light and dark stripes arranged in an angled configuration200 such as shown in FIG. 2A, a square wave configuration 210 such asshown in FIG. 2B, a saw-tooth configuration 220 such as shown in FIG. 2Cand so on. Although specific shapes and patterns are mentioned, theencoding pattern 165 may also be arranged in a sine wave and variousother patterns having both an axial component and a radial component.

Further, although light stripes and dark stripes are specificallymentioned and shown in the figures, the encoding pattern 165 may consistof various types of stripes having various shades or colors that providesurface contrasts. For example, the encoding pattern may include astripe or marking that has a high reflective surface and another stripethat has a low reflective surface regardless of the color or shading ofthe stripes or markings. In another embodiment, a first stripe orportion of the first stripe of the encoding pattern may cause specularreflection while a second stripe or a portion of the second stripe ofthe encoding pattern 165 may cause diffuse reflection. When thereflected light is received by the photodiode array 180, a determinationmay be made as to the position and movement of the shaft such asdescribed below. In embodiments where a holographic or diffractivepattern is used, the light from the light source will diffract from theshaft. Based on the diffracted light, the photodiode array 180 maydetermine the position, movement and direction of movement and type ofthe shaft.

The stripes of the encoding pattern 165 may extend both axially andradially along the shaft 160. The stripes may extend along the entirelength of the shaft 160 or partially along a length of the shaft. Inaddition, the encoding pattern 165 may also be disposed around theentire circumference of the shaft 160. In other embodiments, theencoding pattern may include a radial component. In yet otherembodiments, the encoding pattern may have both a radial component andan axial component. For example, the encoding pattern may extend axiallyalong the shaft 160 for a first distance, then extend radially acrossthe shaft 160 for a second distance, extend axially along the shaft 160for a third distance and so on. The first, second and third distancesmay all be different distances, similar distances or substantiallysimilar distances. Further, each of the first, second and thirddistances may have the same width or different widths.

In another embodiment, the encoding pattern 165 may be disposed only oncertain areas of the shaft 160. For example, if a shaft 160 wasconfigured to have partial rotational movement about an axis in a givendirection (instead of full rotational movement about the axis such asdescribed herein), the encoding pattern 165 may only be disposed on aportion of the shaft 160 that would be visible to the photodiode array180 as the shaft 160 is moved in a rotational direction and/or atranslational direction.

The light and dark stripes of the encoding pattern 165 may alternatebetween a light stripe and a dark stripe. In another embodiment, thelight stripes and the dark stripes of the encoding pattern 165 may bearranged in a particular pattern or order. In such embodiments, eachsection of the pattern may indicate a position of the shaft 160.

In another example, the stripes of the encoding pattern 165 may havevarying widths. The varying widths of each stripe may provide a patternthat indicates a position of the shaft 160. For example, a stripe havinga first width may indicate that the shaft 160 is in a first positionwhile a stripe having a second width may indicate the shaft 160 is in asecond position. In still yet another example, the different widths ofeach of the strips may be used to determine linear movement of the shaft160 as well as rotational movement of the shaft 160.

The stripes of the encoding pattern 200 may also be arranged indifferent patterns. For example, the stripes of the encoding pattern 200may arranged in a QR code, a bar code or other such pattern that may beused to determine a rotational, translational, or angular movement ofthe shaft 160 as well as the movement speed of the shaft 160.

Referring back to FIG. 1B, the optical encoder of the present disclosurealso includes a photodiode array 180. The photodiode array 180 may beseparated into a number of quadrants or otherwise divided into varioussections. Each quadrant of the photodiode array 180 is configured toreceive light that is reflected off of the shaft 160. Specifically, thephotodiode array 180 is configured to receive light of differentintensity values based on whether the light has been reflected off ofthe encoding pattern and in a direction toward to photodiode array in adiffusive manner, in a specular manner or a combination thereof. Theintensity values of the light that is received may then be compared withan intensity value of light received at a previous time to determinemovement direction, speed and the like.

For example, the photodiode array 180 may receive light that isreflected off of the encoding pattern 165. Specifically, as light fromthe light source 170 hits the various stripes of the encoding pattern165, the light is reflected off of the light stripes in a specularmanner and reflected off of the dark stripes in a diffusive manner. Thevarious intensities of the reflected light are then received by thephotodiode array 180 which then converts the reflected light into anoutput current.

Thus, the higher the output current from the photodiode, the more thelight stripe, or the reflective stripe, is seen by the quadrants in thephotodiode array 180 (or seen by a particular photodiode of thephotodiode array 180). Likewise, the smaller the output current, themore the dark stripe, or non-reflective surface, is seen by thephotodiode array 180 (or seen by a particular photodiode or quadrant ofthe photodiode array 180).

Based on the above, rotational and translational movement of the shaft160 and ultimately the crown 140 may be determined. For example,rotational data may be derived from analyzing the outputs of thephotodiodes in the photodiode array 180 across various sample frames.The variance of the outputs in a given time between the sample frames isrelated to the motion or rotational direction of the stripes of theencoding pattern 180 and ultimately the shaft 160.

Referring to FIG. 3, FIG. 3 illustrates an exemplary segmentedphotodiode array 300 according to embodiments of the present disclosure.The photodiode array 300 may be similar to the photodiode arraysdisclosed herein. For example, photodiode array 300 may be similar tophotodiode array 180 described above with respect to FIG. 1B and FIG. 1Cor may be similar to photodiode array 530 described below with respectto FIG. 5A and FIG. 5B.

As shown in FIG. 3, the photodiode array 300 may be segmented intovarious quadrants such, as, for example, quadrant A, quadrant B,quadrant C and quadrant D. Although the photodiode array 300 is shown invarious segments, the photodiode array 300 may be arranged in any twodimensional pattern (either segmented or not) that may receive lightreflected off of an optical encoder as the optical encoder moves in atranslational manner and a rotational manner.

Light from the light source is reflected off of an encoding pattern andreceived by each quadrant. Values of current received by each quadrantmay then be combined and analyzed to determine translational and/orrotational movement of an encoding pattern. Specifically, a change incurrent values between pairs of quadrants may be compared againstpreviously received values to determine the movement.

For example, current values received in quadrant A and quadrant B(either separately or combined) may be compared with current valuesreceived in quadrant C and quadrant D (either separately or combined)over a time period t to detect translational movement of a shaft of anencoder. Likewise, current values received in quadrant A and quadrant Cmay be compared with current values received in quadrant B and quadrantD over a time period t to detect rotational movement of the shaft of theencoder.

In embodiments, the values received in each quadrant may be comparedsimultaneously or substantially simultaneously. For example, adetermination of translational movement may be determined simultaneouslyor substantially simultaneously with a determination of rotationalmovement and vice versa based on output from the photodiode array 300.

In some embodiments, an update to a display may only occur iftranslational or rotational movement exceeds a threshold. For example,if the photodiode array 300 detects movement in both a translationaldirection and in a rotational direction simultaneously or substantiallysimultaneously, a display will be updated only if the movement of theshaft exceeds a given threshold. In another example, a display may onlybe updated if a change in current output provided by the photodiodearray 300 exceeds a particular threshold.

Referring to FIG. 4A-FIG. 4C, FIG. 4A-FIG. 4C show exemplary currentoutput graphs provided by a photodiode array. For example, each graph400, 410, and 420 represent output provided by a photodiode array as itreceives light that is reflected off of an encoding pattern. Asdiscussed above, the sensor that is used to detect movement of the shaftof the optical encoder may be any type of sensor. Thus, the output shownin FIGS. 4A-4C are but one example of output provided by a sensor.

For example, the graph 400 shown in FIG. 4A may represent output of aphotodiode array over a time t. In a subsequent time period, the outputof the photodiode array may look like the output provided by graph 410of FIG. 4B. When compared with the output of the graph 400 of FIG. 4A,it can be determined that the shaft of the encoder is rotating in aparticular direction or that the shaft of the encoder has moved in atranslational direction (e.g., pushed inward). Similarly, when theoutput of graph 420 shown in FIG. 4C is compared with the output ofgraph 400, it can be determined that the shaft of the encoder isrotating in another direction or is moving in another translationaldirection (e.g., pulled outward). More specifically, as the photodiodesin the photodiode array take multiple sequential samples and compare thesamples with at least one previous sample, rotational and translationalmovement is able to be determined based on the current output of thephotodiode array.

In addition to the rotational information, the current output from thephotodiode array may be used to determine a speed at which the shaft isrotating or moving. In embodiments, the speed of the movement of theshaft is determined based on how quickly the pattern of reflected lightchanges. Once the movement direction and speed are determined, output ona display of the electronic device may be adjusted accordingly. Inaddition, the output provided by the photodiode array may be used todetect the angular rotation of the shaft in a similar manner.

Referring back to FIG. 1B, the light source 170 of the electronic device100 may be any type of emitter that provides a light that can bereflected off of the shaft 160 to be received by the photodiode array180. For example, the light source 170 may be an LED, an infrared lightsuch as, for example an infrared LED, a linear light source, a laserdiode, a light bulb and the like.

In embodiments when the light source 170 is an infrared light source,the encoding pattern 165 disposed on the shaft 160 may be invisible tothe human eye but the overall movement determination may operate asdescribed above. For example, a first set of stripes of the encodingpattern 165 may be IR-absorptive and a second set of stripes of theencoding pattern 165 may be IR-reflective. The photodiode array mayreceive the IR-reflective light when the IR-reflective stripe is shownand less light as the shaft turns. Accordingly, a determination ofrotational movement may be made as described above.

In embodiments, the light source 170 and the photodiode 180 are axiallyaligned with respect to the shaft 160. In another embodiment, the lightsource 170 and the photodiode 180 may be radially aligned with respectto the shaft 160. Although specific alignments are disclosed, in certainembodiments the light source 170 and the photodiode array 180 may bealigned with the shaft 160 in any suitable manner so long as light isemitted from the light source 170 is reflected off of the encodingpattern 165 on the shaft 160 and received by the photodiode array 180.

Depending on the use of the shaft 160, the length of the shaft 160 mayvary between embodiments. For example, in some embodiments, the lengthof the shaft 160 may extend along a length or width of the housing 110.In another embodiment, the shaft 160 may have a length that issubstantially less than a length or width of the housing 110.

In addition to the above, the distance in a z direction between theshaft 160 and the light source 170 and the photodiode array 180 may alsovary. Generally, it should be noted that, as the z distance between theshaft 160 and the light source 170 and the photodiode 180 increases, thepattern of light reflected off of the shaft 160 increases in size.Specifically, the number of samples in a given time frame decreases.Likewise, as the z distance between the shaft 160 and the light source170 and the photodiode array 180 decreases, the pattern of lightreflected off of the shaft 160 decreases in size. More specifically, thenumber of samples in a given time frame increases. As the number ofsamples increase, the rotational direction and the rotation speed of theshaft may be better determined.

FIG. 1C illustrates a cross-sectional view of the electronic device 100according to another embodiment of the present disclosure. As shown inFIG. 1C, the electronic device 100 includes similar components to thosedescribed above with respect to FIG. 1B. For example, the electronicdevice 100 includes an optical encoder that consists of a shaft 160, alight source 170 and a photodiode array 180. The shaft 160 includes anencoding pattern 165 that has both axial components and radialcomponents. Further the optical encoder may be used to detect rotationalmovement and translational movement (as shown by arrow 185).

In addition to the components described above with respect to FIG. 1B,the electronic device 100 shown in FIG. 1C includes a sealing portion190 and a button 195. Referring to the sealing portion 190, the sealingportion 190 may be used to protect the encoder wheel from outsideelements that may cause damage or otherwise corrode the encoding pattern165 or the shaft 160. In embodiments, the sealing portion 190 may beused to fully seal all of the components of the optical encoderincluding the photodiode array 180 and the light source 170.

The sealing portion 190 may be made of glass, plastic, sapphire or othertransmissive material. In embodiments, only the portion of the sealingportion 190 through which light from the light source 170 passes istransmissive. In other embodiments, all, or substantially all of thesealing portion 190 may be made from the same material. Further, thesealing portion 190 may be rounded, rectilinear, square and so on.

In embodiments, the space between the sealing portion 190 and the restof the components of the optical encoder may be filled with air, inertgas, a liquid (e.g., an oil lubricant) or may be a vacuum space. Use ofsuch materials may prevent or help to prevent rust and/or reduce wearand tear on the various components of the optical sensor.

The sealing portion 190 may also include a button 195. In embodiments,the button 195 may be a mechanical tac switch that creates a switchclick but contains no electronics. Thus, when a user pushes on the crown140 of the electronic device, the user feels actuation of a button.However, translational movement of the optical encoder such as describedabove, provides the data regarding the “button press.” In otherembodiments, button 195 may include all electronics of a button andprovide signals when actuated.

FIG. 5A-FIG. 5B illustrate an optical encoder 500 according to one ormore embodiments of the present disclosure. In embodiments, the opticalencoder 500 may be similar to the optical encoder shown and describedwith respect to FIG. 1B and FIG. 1C.

As shown in FIG. 5A, the optical encoder 500 includes a shaft 510, alight source 540 and a photodiode array 530. The shaft 510 includes anencoding pattern 515. The encoding pattern 515 may include a pluralityof different colored stripes or shaded stripes that have an axialcomponent and a radial component. For example, as shown in FIG. 5A, thestripes of the encoding pattern 515 may wrap around a circumference ofthe shaft 510 along a length of the shaft 515.

In other embodiments, the stripes of the encoding pattern may alternatein color, width, length and the like. For example, a first stripe of theencoding pattern 515 may be in a first color, a second stripe of theencoding pattern 515 may be in a second color and a third stripe of theencoding pattern 515 may be in a third color. As different colors may beused, the photodiode array 550 may be color-sensitive. Accordingly thechange in color in the encoding pattern 515 as the shaft rotates aboutit axis may be used to determine rotational and translational movementof the shaft 510 as well as movement speed of the shaft 510.

In certain embodiments, the stripes of the encoding pattern 515 may beconfigured to cause specular reflection and diffuse reflection. Forexample, the light 545 from the light source 540 may be reflected ineither or both of a specular manner or in a diffusive manner from theshaft to the photodiode array 530. When the light 545 is received by thephotodiode array, a current, based on the intensity of the light, isused to determine a current position of the shaft. When the shaft ismoved, the change in light intensity or current that is output from thephotodiode array is used to determine translational and/or rotationalmovement of the shaft 510 such as described above.

Although embodiments shown and described discuss the use of both lightand dark stripes in the encoding pattern, in certain embodiments, theentire shaft 510 may be specular (e.g., the entire shaft 510 enablesspecular reflection). In such embodiments, the shaft 510 may have one ormore striations, flutes, channels and the like.

For example, a shaft of an optical encoder may include a plurality ofsurface forms, such as, for example one or more flutes, channels and thelike. The surface forms may include be axially aligned with respect tothe shaft, radially aligned with respect to the shaft or a combinationthereof. These surface forms may cause light to be reflected from theshaft even if there is no variation in color or reflectance from theshaft. In embodiments, the surface forms may be added to the shaftduring the manufacturing process or may be a natural byproduct (orotherwise present) in the shaft due to a machining process.

In embodiments where the surface forms are present, the shape of the oneor more surface forms in the shaft may cause the light from a lightsource to be reflected from the shaft in many different angles and bereceived by a photodiode array thereby simulating diffusion. In suchembodiments, the surface forms may vary in size or have the same orsubstantially the same size. In other embodiments, the shaft may includesurface forms as well as one or more light and/or dark stripes of anencoding pattern such as described above. As such, both features maythen be used in conjunction to determine rotational and/or linearmovement and speed such as described above.

Referring back to FIG. 5A, the optical encoder 500 may include a lightsource 540 and a photodiode array 530. In embodiments, the light source540 may be axially aligned or radially aligned with the photodiode array530 or with the shaft 510.

The photodiode array 530 may be segmented into quadrants such asdescribed above. In another embodiment, the photodiode array 530 may bea two dimensional array having a n rows and m columns. For example asshown in FIG. 5A, the photodiode array 530 may be a four by twophotodiode array. However, the number of photodiodes in the twodimensional photodiode array may increase or decrease depending on thesize of the collection area of each of the photodiodes. For example, anaccurate rotational or linear movement of the shaft 510 may be collectedfrom an array of two photodiodes. In other embodiments, eight or morephotodiodes may be required. In another embodiment, multiple arrays ofphotodiodes may be used. Further, each of photodiode arrays may bearranged in various alignments and positions with respect to the shaft510.

In another embodiment, the photodiode array 530 may be arranged such asshown in FIG. 5B. As shown, at least one portion of the photodiode arrayis axially aligned with the respect to the shaft 510 or morespecifically, at least one stripe of the optical encoder is axiallyaligned with respect to the photodiode array 530. In such arrangement, afirst portion of the photodiode array 530 may be used to determinerotational movement while a second portion of the photodiode array maybe used to determine translational movement.

In yet another embodiment, a portion of the photodiode array 530 may beoffset from the encoder in a push or a pull direction. Thus, any changein light intensity received by the offset portion of the photodiodearray would indicate translational actuation of the of the shaft 510.

FIG. 6 illustrates a method 600 for collecting and determining movementof a shaft of an optical encoder according to one or more embodiments ofthe present disclosure. In embodiments, the method 600 may be used todetermine rotational movement of the shaft, angular movement of theshaft, translational movement of the shaft as well as a speed ofmovement of the shaft. Further, the method 600 described below may beused with the embodiments shown and described above with respect to FIG.1A through FIG. 5B.

The method 600 begins by causing light from a light source to bereflected off of an encoding pattern that is disposed on a shaft of anoptical encoder. The encoding pattern disposed on the shaft may includea plurality of light and dark stripes that have one or both of an axialcomponent and a radial component.

In another embodiment, the shaft of the optical encoder may include oneor more surface components. In such embodiments, the surface componentsmay be used to reflect light in a variety of different directions. Thesurface components may be used in conjunction with the light and darkmarkings of the encoding pattern. In alternative embodiments, thesurface components may be used without the need of either one or both ofthe light markings of the encoding pattern or the dark markings of theencoding pattern.

In operation 620, the light that is reflected off of the encodingpattern is received by a photodiode array. More specifically, light thatis reflected off of the encoding pattern is received by variousquadrants of the photodiode array. When the photodiode array receivesthe reflected light, an initial position of the shaft may be determined.Specifically, as light is reflected from the encoding pattern andreceived by the quadrants of the photodiode array, pairs of quadrants ofthe photodiode array output a current which represents the amount oflight and dark stripes that are in view of the respective quadrants ofthe photodiode array. This output current may then be used to representa position of the shaft at a time t.

Flow then proceeds to operation 630 in which movement of the shaft isreceived. In embodiment, the movement may be rotational movement,translational movement, angular movement or combinations thereof. Forexample a crown of an electronic device may be rotated to change anoutput on a display such as described above. In another embodiment, thecrown may be pushed inward or pulled outward.

Flow then proceeds to operation 640 in which light from the newlyexposed portion of the encoding pattern is received by the quadrants ofthe photodiode array. When the newly reflected light is received, thequadrants of the photodiode array output a current based on theintensity of the reflected light.

Once the reflected light from the newly exposed encoding pattern isreceived, operation 650 provides that the data output by the quadrantsof the photodiode array is analyzed to determine a direction of movementof the shaft. In embodiments, the speed of the movement of the shaft mayalso be determined.

Specifically, operation 650 provides that data output by specificquadrants of the photodiode array from operation 620 above may becompared against data output by the photodiode array from operation 640.For example, the comparison of light intensity received by quadrants Aand B (FIG. 3) versus the light intensity received by quadrants C and Dat a first time is compared with light intensity received by quadrants Aand B versus quadrants C and D at a second time to determine whether anytranslational movement occurred. Likewise, the comparison of lightintensity received by quadrants A and C (FIG. 3) versus light intensityreceived by quadrants B and D at a first time is compared against lightintensity received by quadrants A and C versus light intensity receivedby quadrants B and D at a second time to determine if rotationalmovement has occurred.

Further, operation 650 may be used to determine a speed of rotation ofthe shaft. For example, as the photodiode array outputs the detectedchange in current, the speed of the change may also be monitored. Thechange in speed may then be used to determine the overall speed of themovement of the shaft.

In operation 660, output is generated based on the determined directionof the movement of the shaft. For example, as a crown of an electronicdevice is rotated or otherwise moves, one or more icons or images adisplay of the electronic device may need to be updated accordingly. Forexample, if the display of the electronic device is displaying a timekeeping application, the crown of the electronic device may be rotatedin either direction to change or adjust the position of the hands thatare displayed by the time keeping application. Specifically, the handsthat are displayed by the time keeping application may move in thedirection and speed indicated by the determined movement and speed ofthe shaft such as described above. If translational movement isdetermined, a specific functionality (e.g., selection of an icon) may beperformed.

Although embodiments have been described above with respect to arotational and translational movement of a shaft of an electronicdevice, embodiments of the present disclosure are not so limited. Forexample, the crown of the electronic device shown with respect to FIG.1A could be replaced by a keycap for a keyboard. Thus, each key of thekeyboard may be optically encoded for translational movement or othertypes of movement. In other embodiments, the optical encoder disclosedherein could be used with a button a sliding switch and the like.

Embodiments of the present disclosure are described above with referenceto block diagrams and operational illustrations of methods and the like.The operations described may occur out of the order as shown in any ofthe figures. Additionally, one or more operations may be removed orexecuted substantially concurrently. For example, two blocks shown insuccession may be executed substantially concurrently. Additionally, theblocks may be executed in the reverse order.

The description and illustration of one or more embodiments provided inthis disclosure are not intended to limit or restrict the scope of thepresent disclosure as claimed. The embodiments, examples, and detailsprovided in this disclosure are considered sufficient to conveypossession and enable others to make and use the best mode of theclaimed embodiments. Additionally, the claimed embodiments should not beconstrued as being limited to any embodiment, example, or detailprovided above. Regardless of whether shown and described in combinationor separately, the various features, including structural features andmethodological features, are intended to be selectively included oromitted to produce an embodiment with a particular set of features.Having been provided with the description and illustration of thepresent application, one skilled in the art may envision variations,modifications, and alternate embodiments falling within the spirit ofthe broader aspects of the embodiments described herein that do notdepart from the broader scope of the claimed embodiments.

We claim:
 1. An optical encoder for an electronic device, the opticalencoder comprising: an elongated shaft; a crown attached to a first endof the elongated shaft; a set of surface forms disposed on the shaft,the set of surface forms created as a byproduct of forming the shaft; anoptical sensor comprising a light emitter configured to emit lighttowards the set of surface forms; a plurality of photodiodes arranged inan array and configured to receive diffusively reflected light from theset of surface forms; and a processor operably connected to theplurality of photodiodes; wherein: a rotational movement of theelongated shaft changes the diffusely reflected light; a translationalmovement of the elongated shaft changes the diffusely reflected light;changes in the diffusely reflected light produce changes in an output ofthe plurality of photodiodes; the processor is configured to analyzechanges in the output of the plurality of photodiodes and determine adirection of rotation of the elongated shaft when the elongated shaft isrotated; the processor is configured to analyze changes in the output ofthe plurality of photodiodes and determine a direction of translation ofthe elongated shaft when the elongated shaft is translated; and theprocessor is configured to analyze changes in the output of theplurality of photodiodes and determine the direction of rotation and thedirection of translation when the elongated shaft is rotated andtranslated.
 2. The optical encoder of claim 1, wherein a portion of theoptical sensor is radially aligned with respect to the elongated shaft.3. The optical encoder of claim 1, further comprising a plurality ofmarkings on the elongated shaft, wherein a first set of the plurality ofmarkings comprises a light marking and wherein a second set of theplurality of markings comprises a dark marking.
 4. The optical encoderof claim 3, wherein the plurality of markings alternate along theelongated shaft between a dark marking and a light marking.
 5. Theoptical encoder of claim 1, further comprising a sealed portion disposedaround the elongated shaft.
 6. The optical encoder of claim 1, whereinthe optical sensor is divided into quadrants.
 7. The optical encoder ofclaim 1, further comprising a switch.
 8. The optical encoder of claim 7,wherein the switch is configured to provide a mechanical feel.
 9. Theoptical encoder of claim 1, wherein the plurality of photodiodes arearranged in at least two arrays.
 10. The optical encoder of claim 3,wherein the dark marking causes diffuse reflection of the emitted light,and the light marking causes specular reflection of the emitted light.11. The optical encoder for an electronic device of claim 1, wherein theemitted light is received at the plurality of photodiodes withoutpassing through an intervening structure.
 12. The optical encoder ofclaim 1, wherein: the processor is configured to use multiple sequentialsamples of the output of the plurality of photodiodes to detect a speedof the rotational movement of the elongated shaft; and the processor isconfigured to use the multiple sequential samples of the output of theplurality of photodiodes to detect a speed of the translational movementof the elongated shaft.
 13. An electronic device comprising: aprocessor; a memory; and an optical encoder, wherein the optical encodercomprises: an elongated shaft having a plurality of markings formed as abyproduct of machining the elongated shaft and disposed around acircumference of the elongated shaft; a crown attached to a first end ofthe elongated shaft; a light emitter configured to emit light towardsthe elongated shaft; and an array of photodiodes configured to receivediffusively reflected light from the elongated shaft; wherein:rotational and translational movements of the elongated shaft eachproduce changes in reception by the array of photodiodes of thediffusely reflected light from the plurality of markings; an output fromthe array of photodiodes changes in response to the changes in receptionof the diffusely reflected light; and multiple sequential samples of theoutput from the array of photodiodes are compared by the processor todetermine directions of the rotational and translational movements ofthe elongated shaft.
 14. The electronic device of claim 13, wherein thelight emitter is a laser diode light source.
 15. The electronic deviceof claim 13, further comprising a sealing component disposed around theelongated shaft.
 16. The electronic device of claim 15, wherein thesealing component comprises a transmissive window.
 17. The electronicdevice of claim 16, wherein the transmissive window enables light fromthe light emitter to pass through and reflect off of the plurality ofmarking.
 18. The electronic device of claim 13, further comprising amechanical switch, wherein the mechanical switch is configured to beactuated by the elongated shaft.
 19. The electronic device of claim 13,wherein the elongated shaft includes an encoding pattern comprising aplurality of colored strips helically extending along the shaft.
 20. Theelectronic device of claim 13, wherein the emitted light that isreflected from the elongated shaft is received at the array ofphotodiodes without passing through an intervening structure.
 21. Amethod for detecting a movement of a shaft contained within a housing ofan electronic device, the method comprising: causing a light source toemit light toward a circumference of the shaft, wherein: the shaftincludes encoding forms formed as a byproduct of a machining operationcarried out on the shaft; a crown is attached to a first end of theshaft; and at least a portion of the encoding forms causes the lightemitted from the light source to be diffusely reflected off of theshaft; while the shaft undergoes the movement, receiving the diffuselyreflected light at a photodiode array, wherein; the movement of theshaft includes rotational movement of the shaft and translationalmovement of the shaft; and the movement of the shaft changes thediffusely reflected light to produce a change in an output current of atleast one photodiode in the photodiode array; for the at least onephotodiode in the photodiode array, comparing an output current at afirst time period to an output current at a second time period; anddetermining a direction of the rotational movement of the shaft and adirection of the translational movement of the shaft based on thecomparison.
 22. The method for detecting movement of a shaft of claim21, wherein the emitted light that is reflected from the shaft isreceived at the photodiode array without passing through an interveningstructure.